Maintenance work at the Farmland Industries Inc. plant southeast of town pushed a cloud of low-flung steam into the air Wednesday evening. The steam was the byproduct of the plant's ammonium nitrate production process and at no time posed a risk to the public's health, said Jerry Rockers, the plant's operations superintendent. The Kansas Department of Health and Environment agrees: The steam plume included a trace amount of ammonia, which pales in comparison to the 400 tons airborne ammonia the plant already emits safely each year. ``That in and of itself isn't going to be any risk,'' said Greg Crawford, a KDHE spokesman. ``It's not like it was an entire plume of ammonia.'' KDHE was notified by the plant in advance of the maintenance work and the steam release. The maintenance work -- replacing bearings in a blower that normally prevents steam from being emitted -- lasted 12 hours and the steam stopped flowing by 9:30 p.m. Wednesday, Rockers said. The Farmland plant, just east of Lawrence along the north side of Kansas Highway 10, produces fertilizer.